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'It saved my life': How a smartwatch stopped a woman's health crisis

Heather Hendershot's Apple Watch kept beeping because her resting heart rate was high. She thought it was wrong, but discovered she had hyperthyroidism.

by Meghan Holohan / Apr.12.2018 / 2:15 PM ET / Source: TODAY

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When Heather Hendershot purchased her Apple Watch, she hoped it would encourage her to be more active. She had no idea it would prevent a health crisis.

“I felt totally fine. That is why it was so crazy,” Hendershot, 25, of Scranton, Kansas, told TODAY. “It saved my life because without it, I wouldn’t have known anything was wrong.”

An annoying alarm uncovers a health problem

In the middle of March, Hendershot was watching TV on the couch when her watch started beeping. It had detected her resting heart rate was too high, above 100 beats per minute. (A healthy resting heart rate ranges from 60 to 100 beats per minute.)

Without her Apple Watch, Heather Hendershot might not have learned that she had hyperthyroidism until her health was in serious danger.Courtesy of Heather Hendershot

She was young, had never experienced any heart problems and gave birth to a baby four months earlier with no complications. Hendershot thought she simply was too healthy for something to be wrong.

“I thought, ‘Maybe the watch is a little off or something,’” she said.

Her husband Cody tested it on himself and the watch gave him a normal reading. Hendershot ignored it at first, but the beeping continued over the next 24 hours. It beeped when her heart rate was 110. Then at 120. And again when it reached 140. Cody encouraged her to go to a doctor.

“My husband is a big worrier,” she explained.

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Hendershot went to the emergency room and doctors gave her IV fluids and conducted blood tests. They soon understood why Hendershot’s heart was racing: She had untreated hyperthyroidism, a condition where the thyroid gland produces excessive thyroid hormone.

“I still wasn’t thinking it was that big of a deal,” Hendershot said.

But doctors wanted to monitor her in the intensive care unit (ICU) as they treated her hyperthyroidism and lowered her heart rate. If left untreated, she could develop thyroid storm, a potentially fatal condition where the heart rate, body temperature and blood pressure become dangerously high.

Most people with hyperthyroidism experience more noticeable symptoms

In the ICU, Hendershot met Dr. Alan Wynne, an endocrinologist at Cotton O’Neil Diabetes and Endocrinology Center in Topeka. He was shocked she had not experienced anysymptoms of hyperthyroidism.

“That’s what really stood out most strikingly to me,” he said. “I have been doing this for 27 years — I am pretty sure this is the first time.”

People with hyperthyroidism commonly experience:

Racing heart or palpitations

Sweating

Unexplained weight loss even when eating more

Hair loss

Hand tremors

Nervousness and anxiety

Oily skin

Changes in bowel movements or diarrhea

“Thyroid hormone affects most tissues and organs of the body. It tells our hearts to beat, our intestines when to move,” said Wynne.

People experiencing these symptoms should visit their primary care doctor who can perform a blood test to detect thyroid dysfunction. After an initial diagnosis, doctors perform a scan with a radioactive dye to determine the cause of the thyroid problem.

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According to the American Thyroid Association, the most common cause of hyperthyroidism is Graves’ disease, an autoimmune disease. But there are other causes, such as postpartum thyroiditis, said Wynne. Doctors need to understand the cause before treatment.

“It matters a lot because the treatment options for Graves’ disease is different than thyroiditis,” Wynne said.

At 25, Hendershot had been very healthy. When her resting heart rate increased rapidly, she figured it was a mistake.Courtesy of Heather Hendershot

After a night in the hospital, Hendershot's heart rate and thyroid stabilized, and doctors sent her home. She can’t be tested to determine the cause of her hyperthyroidism until her breast milk dries. For now, she’s on medication to control her heart rate and thyroid. But she hopes others learn from her experience and do not ignore health warnings.

“Pay more attention,” Hendershot said. “Go to the doctor once a year … You don’t have any idea about your health until it gets bad.”